Perforating method and apparatus



March 10, 1942. F. J. CHANDLER 2,275,612

PERFORATING METHOD AND APPARATUS Filed Dec. 11, 1940 2 Sheets-Sheet 1 if five/2%?! W g p1 March 10, 1942.

F. 4. CHANDLER PERFORATING METHOD AND APPARATUS Filed Dec. 11, 3540 q 2 Sheets-Sheet 2 fiaiz/rrmzi'yfiazzz f Z (lame Patented Mar. 10, 1942 UNITED STATES. PATENT OFFICE PERFORATIN G METHOD AND APPARATUS Frank Jermain Chandler, Toledo, Ohio ApplicationDecember 11, 1940, Serial No. 369,586 (01. 164-90) 10 Claims.

This invention relates to the perforating of sheet materials composed partly or wholly of rubber or the like, and has reference more particularly to a method of and machine for puncturing with localized heat at each point of puncture and advancing the material by means of the puncturing members. In general, my present invention is similar to that disclosed in my pending application Serial No. 323,313, filed March 11, 1940.

When preparing sheet rubber, rubber coated fabrics, laminated rubber and fabric sheets and other similar materials for certain uses, such as the manufacture of shoes, clothing and upholstery, it is oftentimes desirable to perforate the sheets "or fabrics to permit ventilation or breathing, as it is commonly called, but because of the elasticity and subsequent processing of the rubber it is difficult to provide satisfactory perforations which are inconspicuous and at the same time sufficiently permanent to be pre served in the final product. Such sheets are perforated preferably before the rubber is cured or vulcanized, and the heating and softening of the rubber which occurs in the curing or vulcanization tends to deform and partly close the per-- forations thus impairing the breathing qualities of the material.

The principal objects of my invention are to provide an improved method and apparatus whereby sheets of the above mentioned character are provided with a multiplicity of properly spaced, uniform openings suitable for ventilation or breathing; to form the openings in a manner to impart permanence thereto and avoid closing thereof or impairment of their breathability in subsequent processing of the material; to obviate mutilation or injury to the material or marring or defacing of any surface pattern thereon; and to impart a rounded shape to the openings or perforations through the pull exerted by the needles in advancing the material, these and other objects being accomplished as pointed out hereinafter and as shown in the accompanying drawings in which:

Fig 1 is a side elevation of a machine embodying my present improvements Fig. 2 is a top view of the machine;

Fig. 3 is an enlarged detail sectional view of the material support and needle assembly taken substantially on the line 3-3 of Fig. 2;

Figs. 4, 5 and 6 are partial views of the structure of Fig. 3 showing three successive positions of the needles in perforating and advancing the work;

Fig. 7 is a plan view of a section of the material with the inserted perforating needle in section and showing the enlargement and rounding of theperforation in advancing the work;

Fig. 8 is an enlarged detail sectional View on the line 8-8 of Fig. 2 showing the slide structure through which the pins are operated to advance the work;

Fig. 9 is a fragmentary side elevation of the cam mechanism which imparts reciprocation to the slide structure of Fig. 8;

Fig. 10 is a side elevation of the cam mechanism which causes the perforating operation; and

Fig. 11 is a fragmentary plan view of the perforated work.

Referring to the drawings, the reference numeral l5 indicates the machine frame which comprises side standards l6 rigidly connected together in suitable spaced relation to accommodate therebetween the sheet material to be perforated. A brace member I! extends between these standards I6 at the top and has secured thereon a work support l8 over which the sheet material I9 is fed from a supply roll 20 to a receiving roll 2i, it being understood that this work support extends between the side standards Hi to afford a continuous support across the top of the machine for the sheet material IS.

The roll 26 is carried on a reel 22 the shaft 23 of which is removably mounted in open top bearings 24 on the opposite side frames l6 respectively and the roll 2| is carried on a reel 25 the shaft 26 of which is likewise removably mounted in open top bearings 2'! on the respective opposite side frames IS. Facilities, hereinafter described are provided tomaintain suflicient slack in the web of material l9 between each roll 20 and 2| and the material support l8 to permit advancing movement of the web across the support I8 by the perforating needles as hereinafter explained, and there are also facilities likewise described hereinafter by which the perforated web is automatically wound on the reel 25 as excess slack occurs at that side of the work support l8.

Mounted on the top of each side standard It is a bracket member 28 (see Fig. 8) formed along the inner edge with an upraised T-shaped slideway 29 of suitable length to accommodate a slide member 30, and each slide member 30 has anupwardly projecting lug 35 to which is pivoted at 32 the respective arm 33 of a wide yoke which is formed with a cross bar 34 which extends across the machine over the work support I8 and carries a series of needles 35 for perforating the work on the support I8. This cross bar 34 of the yoke is normally hel in upraised position by springs 36 interposed between the yoke arms 33 and the side frames l6 and is depressed periodically by cams 31 on a shaft 38 which extends across the machine above the yoke and is journaled in side brackets 39 on the side frames I6, the earns 31 being located directly above the arms 33 to bear thereagainst. A motor 4| mounted on a platform 42 between A pair of links 49 are also provided, one at each side of the machine, pivoted to the outer side of the respective slide member 30 on the pivot 32' thereof and these links extend.v forwardly and upwardly from the pivots 32 and at their forward ends each is provided with anelongated slot 50 through which the shaft 38 extends On the shaft 38 adjacent each link 49 is a cam which engages a roller 52 on the respective link 49 for reciprocating the slide members 30 along the slideways 29, each slide member 30 having a spring 53 interposed beteween the rear end thereof and the frame member 54 to exert a forward sliding tension on the slide member 30.

Thus in each revolution of the shaft 38 the yoke member 3334 is depressed by the cams 31 and the slides 30 are also reciprocated carrying the yoke 33-34 therewith, the cams 31 and 5! being so arranged and the cam 5 I- formed as shown in Fig. 9 so that the slides 30 and yoke 33-34 are retracted rearwardly while the yoke is upraised and moved'forwardly whil the yoke is depressed.

The needles 35 which are arranged in a row across the front of the yoke crossbar 34 in suitable spaced relation to provide perforations at desired intervals are projected downwardly through the sheet I 9 on the support I8 when the yoke is depressed by cams 31 andwhile the yoke is moved forwardly by the springs 53 as permitted by the cams 5i, and in this operation the needles 35 not only perforate the sheet material I9, but also While engaged therewith advance the sheet material over the support I8 for the next row of perforations which occur during the next revolution of the shaft 38.

The top face of the work support I8 is preferably recessed to accommodate the die block 55 at the place where the perforating operation occurs and this die block is provided with slots 56 at intervals corresponding to the spacing of the needles 35 to accommodate the ends of the needles which are inserted through the material I9, said slots being of suflicient length to permit free forward movement of the needles 35 as the latter are moved forwardly to advance the work. Preferably also the work support I8 is recessed at 51 under the slots 56 to afford ample depth for insertion of the needles 35 through the material l9. v

For mounting the needles 35 on the yoke crossbar 34 the latter is provided on its front face with an angle iron 58 having a narrow flange 59 at the bottom with apertures 69 at suitably spaced intervals to receive the needle stems and on the front face of this angle iron 58 above the flange 59 is a seating plate 6| for the needle shanks 62 formed with a shoulder 63 at the top and a bead 64 along the bottom by which the needles are locatable at the proper uniform elevation. A clamp plate 65 is secured by bolts 66 to the front of the yoke crossbar 34 and has along its upper edge a flange 61 which bears against the front face of the yoke crossbar 34 and at its lower edge a flange 68 with beveled edge, as'shown in Fig. 3, which bears against the shanks B2 of the needles 35 and holds same securely in positionagainst the seating plate 6 I.

For perforating sheet rubber, rubber coated fabrics, laminated rubber and fabric sheets and other similar materials, it is desirable to heat the needles not only to facilitate penetration of the needles through the rubber material, but also to cause an incipient vulcanization of the rubber around the perforation to give permanence to the opening and. prevent mutilation or closing of the opening which otherwise is likely to occur in the subsequent processing of the material as ex plained inmy aforesaid application Serial No. 323,313. For heating the needles for this purpose an electrical heating element 69. preferably of a well known type comprising a resistance 10 embedded in insulation H and enclosed in a metal' sheath I2 is clamped by the plate 65 against the needle shanks 62 and connectedwith a suitable source of electric energy controlled by a thermostat in a well known manner to maintain the needles 35 at the required temperature for easy penetration and incipient vulcanization of the rubber immediately around each opening formed in the material I9 by the needles.

To facilitate withdrawal of the needles'35 from the material I9 after each perforating operation a stripper plate I3 is provided which extends across the machine above the work support I8. This stripper plate which is spaced above the work support I8 a sufficient distance to provide clearance for free advancing movement of the sheet material 59 between the stripper plate and work support may be mounted on angle irons I4 secured at their opposite ends to the side frames I6, and this stripper platevhas slots I5 therethrough corresponding to'the slots 55 of thedie block 55 to receive the needles 35 therethrough in the perforating operation and permit the forward movement of the needles for advancing the work.

By reason of the advancement of the work by forward movement of the needles 35 the latter necessarily exert a pull on the work which tends to elongate the perforations 16. Preferably the openings I6 are round or substantially round, and in order to compensate for the stretching or elongation of the openings I6 occasioned by the'pull of the needles in advancing the work and insure,

round or substantially round openings IS in the finished material I9, the needles 35 are preferably formed oval in cross section as indicated at IT in Fig. 7 with the minor axis of the oval extending in the direction of the pull exerted on the material I9 in advancing same acrossthe work support I8 so that an oval opening is formed in the sheet material by each needle 35 as the latter penetrates the material I9 and as the needles are projected forwardly to advance the work of elongation of the openings re-forms the oval opening into an opening of substantially circular form as indicated in Fig; '7, thereby insuring substantially round openings in' the finished material.

In order to permit advance movement of the material I9 by the needles 35 across the work support I8 and hold the material in proper position on the work support while the needles are withdrawn, facilities are provided to maintain suflicient slack in the material I9 at each side of the work support I8 to allow freedom for advancing movement while at the same time sufficient tension is imposed thereon to prevent displacement of the material on the support I8 while the needles are withdrawn. To this end a pair of rolls I8 and I9 are provided at the front of the machine between which the perforated material I9 passes to the roll 2|, one ofwhich rollsl, for

example the roll 19 is operated by a motor 80 through the worm 8| and worm wheel 82 to advance the perforated sheet to the roll 2| .under control of a roller 83 resting on the perforated sheet l9 between the work support [8 and the rolls Hi-19. This roll 83 is carried by a frame 84 pivoted on the frame standards lG--I6 and this frame 84 is provided with a mercury switch 86through which current is supplied to the motor 80, the arrangement being such that when the slack in the sheet l9 between the work support [8 and the rolls l8-19 exceeds a certain amount, the roll 83 on the material [9 will depress sufficiently to close the mercury switch 86 and cause operation of the motor to advance the perforated sheet l9 between the rolls l8 and 19 and when these rolls l8 and 19 have operated sufficiently to diminish to a predetermined extent the slack in the sheet l9 between the work support [8 and the rolls 18-19, the roll 83 will be raised sufficiently to open the mercury switch 86 whereupon the motor 80 ceases operation. Thus a predetermined slack is automatically maintained in the perforated sheet material between the work support l8 and the rolls 18-19.

It is preferred to wind the perforated sheet on the reel 25 as it is fed between the rolls [8 and 19 and for this purpose the shaft 26 of said reel is provided with a pulley 8'! engaged by the belt 88 trained about a small pulley 89 on the shaft 38 to exert a constant winding tension on the drum 25, it being understood of course, that the belt 88 engages the pulley 89 sufficiently loosely to permit slippage when the reel 25 is not free to turn.

Similar facilities are provided tofeed the unperforated material [9 from the reel 22 which is operated by a motor 90 through the worm 9| and worm wheel 92 on the shaft 23. A roller 93 which rests on the sheet material I9 between the work support I8 and reel 22 is carried on a swinging frame 94 which is provided with a mercury switch 95 which controls the operation of the motor 90 in a manner similar to the switch 86 of the motor 80 so that as the amount of slack in the material l9 between the reel 22 and work support I8 is reduced to a predetermined extent, the roll 93 is lifted and the mercury switch 95 closed to operate the motor 90 which then unwinds the material [9 from the reel 22 until the roll 93 drops down to a position to open the mercury switch 95 and discontinue the operation of the motor 90. Thus the material is automatically supplied from the reel 22 to maintain a predetermined amount of slack between the reel 22 and the work support l8 and the perforated material is automatically advanced between the rolls [8 and I9 to maintain a certain amount of slack in the perforated material between the work support I8 and the rolls 18 and I9 and the perforated material is automatically wound on the reel 25 as it is fed between the rolls l8 and 19.

While I have shown and described my invention in a preferred form, I am aware that various changes and modifications may be made therein without departing from the spirit of my invention, the scope of which is to be determined by the appended claims.

I claim as my invention:

1. A method of making perforated sheet material which comprises providing sheet material composed at least partly of rubber or the like, then forming perforations through the sheet material and stretching the perforations to a larger size and locally setting the rubber or like material around each perforation to impart permanence thereto.

- 2. A method of making perforated sheet material which comprises providing sheet material composed at least partly of rubber or the like, then forming perforations entirely through the sheet material and simultaneously subjecting the walls of the perforations to localized heat sufficient to locally soften and partially cure the rubber of said walls, and while subjecting to the localized heat, subjecting the material to such tension as will enlarge the perforations.

3. A method of making perforated sheet material which comprises providing sheet material composed at least partly of rubber or the like, thrusting needles through the sheet material to perforate the same, and while the needles engage the sheet material, imparting relative movement thereto whereby the perforations are enlarged and the material relocated for the next succeeding thrust of the needles.

4. The invention according to claim 3 wherein the needles are heated to locally vulcanize the perforation walls, and the material is under sufficient tension when relatively moved to enlarge the perforations so the needles fit loosely therein.

5. A method of forming perforations of a permanent character in sheet material composed at least partly of rubber or the like, which comprises thrusting heated needles through said material, enlarging the perforations with the needles therein and simultaneously imparting advancing movement to the material through the needles, then withdrawing the needles and positioning them opposite an unperforated area of the material.

6. The invention of claim 5 wherein the needles when engaged with the material are moved in a direction transverse to their length.

7. A method according to claim 5 wherein needles of oval cross section are moved in the direction of the minor axis of the oval to advance the material.

8. In apparatus of the character described, the combination of a work support, a plurality of needles, means to reciprocate the needles to and from the work support to perforate work thereon, means to move the needles laterally in the work penetrating position and thereby advance the work, and tension equalizers at opposite sides of.

the work penetrating position independently operable respectively to allow work to be supplied to and to withdraw work from the work puncturing position.

9. In apparatus of the character described, the combination of a work support, work tensioning means, work feeding means, a plurality of needles of oval cross section, means to move said needles to puncture the work and advance the material, said work tensioning means being constructed and arranged to stretch the oval punctures made by the needles into substantially round openings as the material is advanced.

10. In apparatus of the character described, the combination with a work support, a supply roll, and a receiving roll, of a plurality of needles of oval cross section, means to move said needles to puncture the work and to advance the same, and means to cause stretching of the oval punctures made by the needles into substantially round openings.

FRANK J ERMAIN CHANDLER. 

